1.安装OCCI
如果oracle数据库默认没有安装OCCI,可以自己从官网上下载与自己数据库版本一致的API,其中包含四个软件包:
oracle-instantclient-sqlplus-10.2.0.5-1.i386.rpm
oracle-instantclient-devel-10.2.0.5-1.i386.rpm
oracle-instantclient-odbc-10.2.0.5-1.i386.rpm
oracle-instantclient-basic-10.2.0.5-1.i386.rpm
安装完成之后,会在/usr/lib下多个oracle 共享库文件夹,在/usr/include下多个oracle 头文件(接口)文件夹(可以将他们放到环境变量中)。我的数据库版本是10.2.0,下面以此为例。
2.编写HelloWorld程序测试连接
#include <iostream>
#define LINUXOCCI //避免函数重定义错误
#include <occi.h>
using namespace std;
using namespace oracle::occi;
int main()
{
Environment *env=Environment::createEnvironment(Environment::DEFAULT);
cout《"success"《endl;
string name = "scott";
string pass = "tiger";
string srvName = "127.0.0.1:1522/orcl";
try
{
Connection *conn = env->createConnection(name, pass);
cout《"conn success"《endl;
env->terminateConnection(conn);
}
catch(SQLException e)
{
cout《e.what()《endl;
return -1;
}
Environment::terminateEnvironment(env);
cout《"end!"《endl;
return 0;
}
编译命令:
g++
test.cc -o test -I/usr/include/oracle/10.2.0.5/client -L/usr/lib/oracle/10.2.0.5/client/lib -locci -lsqlplus
我没有将occi的路径加入到环境变量中,所以此处要显示列出目录才能通过编译,找到共享库 www.jx-jf.com
运行。/test会报错,libocci.so找不到,解决办法很简单:将/usr/lib/oracle/…/lib下的库加入到LD_LIBRARY_PATH中就可以了。
输出结果:
success
conn
success
end!
注:这件不幸的事情可能只发生在我身上了,本人系统中有三个用户,其中一个是oracle,而程序是用另一个用户写的,于是编译通过了,但是运行总是报错:
ORA-12162:
TNS:net service name is incorrectly specified
后来查明,这个是由于没有设置并导出ORACLE_SID.换了oracle用户试试,居然运行通过了,真的很伤心,原来那个用户没有设置Oracle环境变脸怎么能直接本地访问呢。
3.进行一些操作,执行sql语句
Employees.h
/*
* A simple OCCI test application
* This file contains the Employees class declaration
*/
#include <iostream>
#include <occi.h>
#include <iomanip>
using namespace oracle::occi;
using namespace std;
class Employees {
public:
Employees();
virtual ~Employees();
void List();
private:
Environment *env;
Connection *con;
string user;
string passwd;
string db;
};
Employees::Employees()
{
/*
69 * connect to the test database as the HR
70 * sample user and use the EZCONNECT method
71 * of specifying the connect string. Be sure
72 * to adjust for your environment! The format
73 * of the string is host:port/service_name
74 */
user = "scott";
passwd = "tiger";
db = "127.0.0.1:1522/orcl";
env = Environment::createEnvironment(Environment::DEFAULT);
try
{
con = env->createConnection(user, passwd, db);
}
catch (SQLException& ex)
{
cout 《 ex.getMessage();
exit(EXIT_FAILURE);
}
}
Employees::~Employees()
{
env->terminateConnection (con);
Environment::terminateEnvironment (env);
}
void Employees::List()
{
/*
104 * simple test method to select data from
105 * the employees table and display the results
106 */
Statement *stmt = NULL;
ResultSet *rs = NULL;
string sql = "select EMPNO, ENAME, JOB " \
"from EMP order by EMPNO";
try
{
stmt = con->createStatement(sql);
}
catch (SQLException& ex)
{
cout 《 ex.getMessage();
}
if (stmt)
{
try
{
stmt->setPrefetchRowCount(32);
rs = stmt->executeQuery();
}
catch (SQLException& ex)
{
cout 《 ex.getMessage();
}
if (rs)
{
cout 《 endl 《 setw(8) 《 left 《 "EMPNO"
《 setw(22) 《 left 《 "ENAME"
《 setw(27) 《 left 《 "JOB"
《 endl;
cout 《 setw(8) 《 left 《 "======"
《 setw(22) 《 left 《 "===================="
《 setw(27) 《 left 《 "========================="
《 endl;
while (rs->next()) {
cout 《 setw(8) 《 left 《 rs->getInt(1)
《 setw(22) 《 left 《 (rs->isNull(2) ? "n/a" : rs->getString(2))
《 setw(27) 《 left 《 rs->getString(3)
《 endl;
}
cout 《 endl;
stmt->closeResultSet(rs);
}
con->terminateStatement(stmt);
}
}
main.cc
#include "Employees.h"
using namespace std;
using namespace oracle::occi;
int main (void)
{
/*
48 * create an instance of the Employees class,
49 * invoke the List member, delete the instance,
50 * and prompt to continue…
51 */
Employees *pEmployees = new Employees();
pEmployees->List();
delete pEmployees;
cout 《 "ENTER to continue…";
cin.get();
return 0;
}